1. Field of the Invention
The present invention relates to shotguns and shotgun barrels and more particularly relates to insert tubes for over and under shotguns that fit the barrel, extending substantially the full length thereof to change the choke of the barrel. Even more particularly, the present invention relates to an improved barrel insert tube having an elongated (preferably aluminum) barrel section, and a shorter heavier chamber section (preferably titanium or steel) that includes an outer surface with a socket that carries a plastic projecting member extending slightly above the shaped outer surface of the chamber section for creating a slight interference fit between the bore at the breech chamber and the tube insert at the plastic projection.
2. General Background
On the of the most common types of shotguns used in competitive skeet shooting is the over/under type shotgun. This shotgun includes two barrels that are vertically aligned and a breech portion that breaks open to expose the chamber ends of the barrels. Such over and under shotguns are well known in the art, manufactured and sold by a number of large gun manufactures such as Browning, Berreta, Windchester, and Remington.
It is known in the art to place a long tubular insert within one or both of these barrels for changing the choke of the barrel. An example of such a tubular insert that changes the choke of the barrel can be seen in U.S. Pat. Nos. 4,989,359 and 5,018,293.